This study examines social desirability bias in the context of ethical decision-making by accountants. It hypothesizes a negative relation between social desirability bias and ethical evaluation. It also predicts an interaction effect between religiousness and gender on social desirability bias. An experiment using five general business vignettes was carried out on 121 accountants (63 males and 58 females). The results show that social desirability bias is higher (lower) when the situation encountered is more (less) unethical. The bias has religiousness and gender main effects as well as an interaction effect between these two independent variables. Women who were more religious recorded the highest bias scores relative to less religious women and men regardless of their religiousness.